Authorities in several U.S. states are reporting that a hacker has once again broken into and defaced electronic road signs over highways. The attack was reminiscent of a series of incidents beginning two years ago in which various electronic message signs were changed to read Warning, Zombies Ahead A report by the Multi-State Information Sharing and Analysis Center (MS-ISAC) points out that these incidents appear to be encouraged by sloppy security on the part of those responsible for maintaining these signs.”]
Source: https://krebsonsecurity.com/2014/06/they-hack-because-they-can/